<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

    </style>
</head>
<body>
    <div id="app">
        {{books}}
        <ul>
            <li v-for="item in books">
                书本数量是<input type="text" v-model.number="item.count">{{item.count}}
                书本名称是{{item.bookName}}
                书本价格是{{item.count * item.price}}
                <button @click="item.count++">click</button>
            </li>
        </ul>
        书本总数是{{bookTotal}}
        书本总价是{{bookPriceTotal}}
    </div>

    <script src="./vue.js"></script>
    <script>
        // 数据驱动
        let myApp = new Vue({
            el: '#app',
            data: {
                name: 'tom',
                msg: '',
                books: [
                    {bookName: 'html', count: 0, price: 8},
                    {bookName: 'css', count: 0, price: 10},
                    {bookName: 'java', count: 0, price: 13},
                    {bookName: 'javascript', count: 0, price: 21}
                ]
            },
            // 计算属性
            computed: {
                // 变量来使用
                bookTotal () {
                    return this.books.reduce((prev, next) => {
                        return prev + next.count
                    }, 0)
                },
                bookPriceTotal () {
                    return this.books.reduce((prev, next) => {
                        return prev + (next.price * next.count)
                    }, 0)
                }
            }
        })
    </script>
</body>
</html>